I can't remember if this was a dream or not, but once when I was young I had a particularly nasty stomach-ache. I had seen an ad for a pill to stop pain during periods and surmised that a period was a bad stomach-ache. I went up to my father and said "Dad, I'm having a period." I couldn't think why he was laughing.
A childhood belief about periods

others believed things like this
- I thought a stomach ache was a stomach egg— Catherine
- My sister told me whenever I had a tummy ache it was my unborn twin inside my stomache trying to get out.— Jamie Field
- I used to believe that i couldn't swallow bubble gum because it would stick to my stomach— Nathalia
- When i was young, i used to believe that when i ate a stone, a tree would grow in my stomach— -yacine-91-
- i was told when i was young that if i swollowed gum my stomach would grow teeth to chew it— gammie
- I used to believe that you had to be on your period to get pregnant........— Tricia